Propeller shaft



Patented May 14,1935 v l d l j i 2,001,166

"unirse fsv'rrrras4 'PATENT oFrlcE PBOPELLEB SHAFT A. Swennes, Rockford,Ill., assignor, by menne assignments, to Borg-Warner Corporation,Chicago, Ill., a corporation of Illinois 'Application November 2v, 1933.serial No. osasss s claims. (ci, 64-29') 'I'hisinvention relates topropeller shafts for monlc resonance. This resonance may be the motorvehicles. result of the vdirect forces', above mentioned, or In theconstruction of motor vehicles considerdue to sympathetic harmonieresonance. That L 'ableattention has been 4given tothe matter of is tosay, the deflections' ofan ordinary tubular absorbing vibration anddeadening sound. Prac. propellerA shaft incident to operation of themotor -V tically every part of the carhas been studied vehicle are foundto cause a distinct noise atwith that object in view but, so far as I amaware, tributable to the resonance of the part. Then, there has been noimprovement made in the protoo, sympathetic vibration of an ordinarytubular peller shaft to overcome the objectionable noise propeller shaftcauses a distinct noise to be heard l0 due to the resonance of thistubular part which at certain critical .speeds where such vibration 1Qasserts itself at certain critical speeds, nor any manifests itself. Thevibrations which the proimprovement with a view to diminishing if notpellet Shaft may fall in With in the Way 0f Symentirely eliminating itssusceptibility to transmit pathetic vibrations, may be created or occureiting vibrations'rcreated or occurring in either of ther in the rearaxle orinany part of the mechthe mechanisms ahead and behind thepropeller anism in front of the propeller shaft, and, of 15 shaft. Itis, therefore, 'the principal object of course, some vibrationsoccurring ahead or hemy invention to provide a non-resonant and vlhindthe propeller shaft may be transmitted dibration dampening propellershaft. rectlv through the propeller shaft unless the same The propellershaft of my invention is tubular is properly constructed to dampen outsuch viand iillec or plugged with a relatively non-resobration. Anordinary propeller shaft being of ,20

nant material to dampen vibration and prevent tubular section also has aharmonic vibration by harmonics from affecting the shaft so that thereason of the closed air space.

phenomenon of resonance is eliminated. In accordance with my invention,I prevent This application is a continuation in part of harmonics fromaffecting the shaft either by nllmy copending application Serial No.615,917, filed ing or plugging the same with a relatively nonu 2:

June 7, 1932. resonant material to dampen vibrationancl elim- Inthedrawinginate the phenomena of resonance. Thus, in Figurev 1 shows apropeller shaft and its univer- Fig. 2, the shaft I0 is shown lled withsteel Wool sal joint connection, the said shaft being filled I8, whichis a relatively non-vibrating material with non-resonant material asindicated by the and will accordingly dampen out the vibration of 30cross-section, Fig. 2; the shaft. Any other suitable material, wheth-Flg.'j3 is a similar section showing'the use of a er metallic ornon-metallic, having similar chardiflerent non-resonant material, andacteristics so far as deadening vibration is con- Fig. 4 is a viewcorresponding in part to Figure cerned could, of course, be used. Fig. 3shows a Y1 illustrating the use of plugs for a similar purlling I9 ofnon-metallic material, such as cork, 35

pose. i cotton, or plaster Paris, selected because of its Similarreference numerals are applied to corvibration dampeningcharacteristics. It is readresponding parts throughout the views. ilyconceivable that while I have shown a metallic Referring flrst to Figure1, the propeller shaft `ilbrous material in Figure 1 and a non-metallic40 is indicated bythe reference numeral III. Itis solid material in Fig.3, a combination of these 40 tubular like other propeller shafts andjoined at materials might be used to good effect. its rear end to theyoke Il of a universal joint InFig. 4, the shaft III' correspondsto theshait ,V y l2 to transmit power t'o the driven spindlein the I 0 withoutany lling but having plugs 20 of rear axle housing of the motor vehicleon which cork or rubber, or 'any other compressible and the propellershaft is mounted. The front end slightly resilient material having sounddeadening 45 `of the shaft carries a splined part I3 received vordampening properties. I prefer the. use of within the slip yoke Il o!the'front universal composition cork as it seems to be best adaptedjoint I5 so as to make connection with the gear forth@ purpose,V Theseplugs are inserted with a, set. 'I'he connections at the front and rearAmay press lit and shifted until, the proper locations be completedthrough the conventional coupling are determined experimentally.Assuming a cor- 50 flanges I 6 and I1,-,or in anygother suitableor rectdiagnosis` of the Veffect secured with these preferred manner. plugs,they are placed at the points of maximum The propeller shaft III issubjected to torsional, vibratory motion. Once the proper locations arecolumn or strut, and beam deflections. Being of determined vit is, ofcourse, unnecessary to go to regular section, itis also subject tonatural harthe trouble of checking for vibration on subse- 55 quentshafts of the same size, the plugs being sufnciently elongated to becertain of spanning the proper points on the shafts to secure thedesired results. 'I'he fact that the plugs are concentric with the shaftinsures against any disturbance of dynamic balance in the turning of theshaft, the same being true, of course, where the shaft is lled. 'I'hereis, of course, an appreciable saving in fixing shafts this way ascompared with lling, and substantially the same results are secured.

It is believed theforegoing description conveys a good understanding ofall of the objects and advantages of my invention. The appended claimshave been drawn to cover all legitimate modifications-and adaptations.

I claim:

l. vA hollow propeller shaft for a motor vehicle power transmissiontrain adapted to have suitable power transmitting connections atopposite-ends, and a plug of non-resonant material frictionally engagingthe inside of the shaft to dampen vibration of the walls thereof.

2. A hollow propeller shaft for a motor vehicle power transmission trainadapted to have suitpower transmitting connections at opposite ends, anda plug of substantially non-resonant material frictionally engaging theinside of the shaft to dampen vibration of the walls thereof, and saidplug being sufficiently elongated whereby to span the proper point onthe shaft when located by approximation.

` 4. A hollow propeller shaft for a motor vehicle power transmissiontrain adapted to have suitable power transmitting connections atopposite -ends, and plugs of substantially non-resonant materialfrictionally 8118881118 the walls of said shaft at the points of maximumvibratory motion to dampen vibration and render the shaft substantiallynon-resonant, and said plugs being suillciently elongated whereby tospan the proper points on the shaft when located by approximation.

wherein the material is compressible and resilient.

the plugs having a press fit in the shaft and relying upon theirresilience for snug frictlonal engagement with the walls of the shaft. H

7. A hollow propeller shaft for a motor vehicle power transmission trainadapted to lhave suitable power transmitting connections at oppositesubstantially `non-resonant, and said plugs being y sufiicientlyelongated whereby to span the proper points on the shaft when located byapproximtion. 'f

BENJAMm: A. swnNNms.

